Since many motherboards are now being manufactured with 2 serial
ports installed, a good alternative is a 4 port card that only has 2
of the ports populated. The boards can address these 2 ports as
COM 3 and 4 at any IRQ's (2-15) that you have open. They cost about
$50 at Comp-USA and Computer City. Taking a good look through
Computer Shopper should get you one for even less. If you need all
4 of the ports, an upgrade kit is available for (I think) $39.00.
My system is configured as follows:
Motherboard
COM1, IRQ 4 - mouse
COM2, IRQ 3 - TNC
Add on card
COM3, IRQ 9 - Rig
COM4, IRQ 12 - Open (Future RTTY)
2 port serial card
LPT1, IRQ 7 - Printer
LPT2, IRQ 5 - Keyer
Other IRQ's
Ethernet IRQ 10
Hard Drive IRQ 11
Sound Card IRQ 15
Now let's see, IRQ 14 is still available.....
73'es
Mike, W1NR
Michael A. McCarthy, President Phone: (508) 460-6737
Everest Engineering Corporation Fax: (508) 460-7951
4 Barnes Circle E-mail wa1uar@eecorp.com
Marlborough, MA 01752
>From k5yf@wt.net (Larry Johnson K5YF) Sun Jan 26 12:17:28 1997
From: k5yf@wt.net (Larry Johnson K5YF) (Larry Johnson K5YF)
Subject: Computer Noise Poll
Message-ID: <BMSMTP85428032716k5yf@pop3.wt.net>
I, too, had problems with the interference from my computer on 7.008, 14.016,
etc. Very frustrating since 40 is my main band, and the interfence on 7.008 was
a killer from 7.005 to 7.010.
I finally solved the problem such that I now have no interference at all. I did
this by grounding my monitor and my 2m packet rig to a common ground point on
the computer, and then that to my station ground bus. The ground point on the
computer is a bolt on the back of the chassis...which happens to be metal. The
ground point on the 2m rig is the hole that is normally used for a bracket
mount. To ground the monitor, I used the screw that holds the connections
bracket in place. On my monitor, the pwr cable and monitor cable go into a
panel that has a screw on both sides to hold it in place. That was the point
used for the monitor ground.
Grounding the monitor to the computer to the station ground bus solved my 40m
interfence (knew it was the monitor because switching out of SVGA windows to
DOS also eliminated the problem). Grounding both the monitor and packet rig to
the computer and station eliminated interfence on the 2m rig, TNC, and monitor
which I was getting when running 700 watts. If your monitor is not grounded as
such, you may wish to give it a try.
* Larry Johnson / K5YF
* Internet: K5YF @ WT.NET
* Houston, Texas U.S.A.
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